Stroke: antihypertensives decrease recurrent stroke.

Clinical bottom line (level 1a)

  1. Patients who have had a previous stroke or TIA and are given antihypertensive therapy are less likely to have a recurrent stroke, than those given placebo (NNT = 40 at unknown) .
  2. Patients given antihypertensives are less likely to have a major cardiovascular event (NNT = 45 at unknown) .
  3. Patients given antihypertensives are less likely to suffer cardiovascular mortality (NNT = 89 at unknown) .
  4. Patients given antihypertensives are less likely to have a fatal stroke (NNT = 107 at unknown) .
  5. There is no clear difference in total mortality, fatal coronary events or major coronary events.
The INDANA Project Collaborators : Stroke 1997; 28: 2557-2562
Expires December 2003

The study

Systematic review of randomised controlled trials of
  • Patients: prior stroke or transient ischaemic attack
  • Intervention: blood pressure lowering drugs compared with placebo
  • Outcome: recurrent stroke, mortality and coronary events


    • Articles found in ?language using unstated databases, no dates given (search terms: ? ) and a survey of specialised and general medical journals, survey of specialised congress proceedings, reading of overviews and direct contacts with investigators involved in such trials.

    Selection criteria: as above
    Appraisal criteria: not detailed
    Articles excluded if: not given

    9 trials including 6752 patients were used.
    There was no significant heterogeneity between the trials.

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    all strokes unknown 317
    (9.47%)    		 237
    (6.96%)    		 26.0%
    (14.0% to 37.0%)    		 2.51%
    (1.20% to 3.82%)    		 40
    (26 to 84)
    major cardiovascular events unknown 380
    (11.4%)    		 311
    (9.14%)    		 20.0%
    (7.00% to 30.0%)    		 2.21%
    (0.77% to 3.66%)    		 45
    (27 to 130)
    cardiovascular mortality weeks 189
    (5.65%)    		 154
    (4.52%)    		 20.0%
    (1.00% to 35.0%)    		 1.12%
    (0.07% to 2.17%)    		 89
    (46 to 1372)
    fatal strokes unknown 111
    (3.32%)    		 81
    (2.38%)    		 28.0%
    (5.00% to 46.0%)    		 0.94%
    (0.14% to 1.73%)    		 107
    (58 to 703)
    total mortality unknown 270
    (8.06%)    		 245
    (7.20%)    		 11.0%
    (-5.00% to 24.0%)    		 0.87%
    (-0.40% to 2.13%)    		 115
    (NNT = 47 to infinity;
    NNH = 250 to infinity)
    fatal coronary events unknown 44
    (1.31%)    		 41
    (1.20%)    		 8.00%
    (-40.0% to 40.0%)    		 0.11%
    (-0.42% to 0.64%)    		 911
    (NNT = 156 to infinity;
    NNH = 237 to infinity)
    all major coronary events unknown 56
    (1.67%)    		 64
    (1.88%)    		 -12.0%
    (-60.0% to 21.0%)    		 -0.21%
    (-0.84% to 0.42%)    		 -482
    (NNT = 237 to infinity;
    NNH = 119 to infinity)

    Citation

    1. The INDANA Project Collaborators , : Effect of antihypertensive treatment in patients having already suffered from stroke: Gathering the evidence. Stroke 1997; 28: 2557-2562
    Contributor: Clare Wotton and Musab Hayatli, December 1999
    Reviewer:

    Clinical Question.
    Patient prior stroke or TIA
    Intervention or Exposure blood pressure lowering drugs
    Comparison placebo
    Outcome recurrent stroke and mortality